416 



SCIENCE 



[N. S. Vol. LII. No. 1348 



The effect of conditions on the relation of seed 

 plants to JS-ion concentration of nutrient solu- 

 tions: B. M. DuGGAR. The results of work previ- 

 ously reported iudieate that in the preparation of 

 salt (or so-called mineral nutrient) solutions for 

 the solution culture of seed plants under the most 

 favorable conditions, consideration must be given 

 to the hydrogen ion coneentration as well as to 

 salt proportions. The hydrogen ion concentrations 

 of carefully prepared and analytically pure mono- 

 basic phosphates are for some plants near or 

 above the critical point for growth maintenance. 

 The effects of changes in the environment, espe- 

 cially temperature and humidity afEect in no simple 

 manner the response of the plant to changes in 

 Ph. The optimum Ph like the optimum tempera- 

 ture may be represented by a considerable range 

 of values and may be defined closely only in rela- 

 tion to other environmental conditions. 

 , The relation of dextrose to hydrogen ion con- 

 centration with B. Coli: "William H. Chambers. 

 By correlating the property of B. coli to produce 

 acid from dexitrose with the property of alkali for- 

 mation in dextrose-free bouillon, it was possible to 

 control the hydrogen ion concentration of a grow- 

 ing culture within a narrow zone by the addition 

 of small amounts of dextrose at frequent inter- 

 vals. The initial amount of dextrose furnished de- 

 termined the maximum hydrogen ion concentra- 

 tion attained. Reversion of reaction is demon- 

 strated in bouillon vrith .3 per cent, or less of dex- 

 trose. Growth curves plotted from plate determi- 

 nations show the inhibitory and lethal effects of 

 alkali and acid. 



The determination of small amounts of chlorine 

 in tissues: Eichard D. Bell and E. A. Doist. A 

 method, based on that of Neumann, is described 

 for the rapid determination of 3-10 mg. of 

 chlorine in tissues. The tissue is digested with 

 sulfuric acid and persulfate and the gases ab- 

 sorbed iu alkali. No cyanide is formed by this 

 digestion process. The sulfur dioxide evolved re- 

 duces hypo-chlorite to chloride. The chlorides are 

 precipitated with standard sUver nitrate. The 

 mixture is concentrated to a small volume, made 

 up to 25 c.e. and filtered. The filtrate is titrated 

 using the solutions of McLean and Van Slyke. 

 For whole Wood and plasma, the results agree with 

 those obtained by Foster's modification of the 

 method of McLean and Van Slyke. 



Pectin studies; I. Effect of pectin on the hydro- 

 gen ion concentration of acid and of alkaline so- 

 lutionis: H. E. Patten and T. O. Kellems. 



The oxidation of acetoacetic acid iy hydrogen 

 peroxide in the presence of glucose: P. A. 

 Schaffer. 



Influence of fermentation on the starch content 

 of experimental silage: A. "W. Dox and Lester 

 YoDEE. A study of experimental corn silage at 

 different stages of fermentation which was normal 

 as regards development of aroma and changes in 

 acidity, alcohol and sugar content, leads to the fol- 

 lowing conclusions: (1) Changes in total acidity, 

 alcohol and sugar are independent of the starch 

 content of the ensiled corn and of the silage pro- 

 duced from it. (2) The first intermediate pro- 

 ducts resultinig from decomposition of starch are 

 not present in demonstrable quantities. (3) The 

 starch content remains constant throughout the 

 fermentation process. (4) The starch granules re- 

 main intact, undergoing no physical change that 

 can be detected by microscopic examination. 



Water-soluhle B vitamines: II. Are the anti- 

 neuritic and the growth-promoting vitamines the 

 same? A. D. Emmett and Mabel Stockholm. In 

 previous work in feeding pigeons and young rats 

 the same basal diet as the only source of water- 

 soluble B vitamine, we found that the antineuritio 

 vitamine (pigeons) and the growth-promoting 

 (rats) were not the same. In further studies, car- 

 ried out on yeast, rats and pigeons, it has been 

 ascertained, by using the Williams quantitative 

 yeast method, that the ' ' vitamine ' ' that stimulates 

 growth in the yeast cell is not antineuritic, as has 

 been claimed, but simply growth-promoting. 

 Further, this "vitamine" apparently has very 

 little if anything to do with the growth of the rat. 

 Therefore, the water-soluble B vitamine appears 

 to be much more complex than many have been led 

 to believe. Charles L. Parsons, 



Secretary 



SCIENCE 



A Weekly Journal devoted to the Advancement of 

 Science, publishing the official notices and pro- 

 ceedings of the American Association for 

 the Advancement of Science 



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